Boulangerite (Weight: 224 g) – Locality: Primiero, Trentino South Tyrol, Italy — Photo: Kaethe17 · CC BY-SA 4.0
Boulangerite
A lead-antimony sulfosalt named in 1837 for French mining engineer Charles Boulanger.
Intro adapted from Wikipedia (CC BY-SA).
Boulangerite is an IMA-recognized mineral species in the sulfosalt class, with the chemical formula Pb₅Sb₄S₁₁.
It crystallizes in the orthorhombic crystal system (space group Pbnm).
Key properties: Mohs hardness 2.5–3; specific gravity 6.2; typically gray; Brownish streak; Metallic, may be silky luster.
IMA symbol Bou, grandfathered status — known before the IMA’s founding, named in 1837.
Found in hydrothermal veins formed at low to medium temperatures.
It is found associated with Lead sulfosalts, galena, stibnite, sphalerite, pyrite, arsenopyrite, siderite, quartz.
The mineral was named to honor Charles Louis Boulanger (1810–1849), French mining engineer, who called attention to the species.
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